Method for fabricating a footwear sole

ABSTRACT

A method for forming a footwear sole is disclosed. Specifically, there is provided a sole mould for fabricating high-quality shoe soles with great efficiency and a method of using such a mould, wherein the soles feature good air permeability and perfect match with the feet by automatically adapting themselves to the shape of the feet. The sole mould includes a first mould for injection-moulding the underside of a leather layer, and a second mould for injection-moulding the upper surface of the leather layer to form the sole. Further, the first mould is configured in the same shape as the fore sole of the foot and the second mould is configured in the shape of a complete sole.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of Chinese Application Serial No.201010572489.1, filed on Dec. 3, 2010, which is incorporated herein inits entirety by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a technology for making footwear, andparticularly relates to a mould for making shoe soles and its usage.

Ordinary shoe soles are generally formed up by one or two types ofmaterials, which have poor air permeability and tend to fatigue the feetafter long-term wear. Besides, they fit badly with the feet and mayeasily cause the fore part of the foot to deform if worn for a longtime.

WO 2010/012401 by O′Connor et al. discloses a footwear outsole 1 made ofa lather lamina 3 with ground contact lugs 4 moulded at the bottom ofthe layer lamina 3 and a series of very thin parallel strips 9 bondedwith adhesive at the top of the leather lamina 3. An outsole moulding 2may be stitched 6 or moulded around the outer edges of the leatherlamina 3. A problem with such outsole 1 is that the lugs 4 and strips 9may become detached from the leather lamina, during use for example,because the bonding between the lamina 3 and the lugs 4 and strips 9 isnot strong enough. Also, using stitching 6 to bond the outsole 2 adds anadditional stitching step using stitching machinery in addition to theother manufacturing and moulding steps using moulding machinery andpotentially increases the costs and complexity.

There is therefore a need in the market for a more durable shoe sole,while maintaining fabrication costs and complexity at low levels.

The present invention discloses a technology which overcomes theabove-mentioned shortcomings by providing a sole which can fit snuglywith the foot, has good air permeability and elegant appearance. It canautomatically adapt to the shape of the foot, and is therefore suitablefor long-term wear.

SUMMARY OF INVENTION

According to a preferred embodiment of the present invention, there isprovided a method for forming a footwear sole comprising a fore sole anda rear sole. The method comprises: providing a midsole layer having oneor more midsole injection holes and one or more midsole boresdistributed thereon, the midsole injection holes and the midsole boresextending between an underside of the midsole layer and an upper surfaceof the midsole layer; providing a first female mould comprising one ormore first downward concave cavities and first raised areas; placingsaid midsole layer onto said first female mould, and aligning saidmidsole injection holes and said midsole bores with said first downwardconcave cavities provided in said first female mould; providing a firstmale mould comprising a first injection area comprising one or more offirst bores and one or more first injection holes; assembling and fixingsaid first male mould and said first female mould so that each of saidmidsole bores and said midsole injection holes are respectively alignedwith each of said first bores and each of said first injection holes;infusing a first formula plastic into said first male mould by way ofsaid first injection holes and said midsole injection holes into saidfirst downward concave cavities, wherein said first formula plastic ischanneled through each of said first injection holes and each of saidmidsole injection holes into each of said downward concave cavities andshaped up resulting in raised soles lines on said fore sole, and furtherwherein said first formula plastic inside each of said first downwardconcaves passes through each of said midsole bores and into each of saidfirst bores to form one or more protuberances which are embedded withsaid midsole layer; splitting said first male mould and said firstfemale mould to remove said midsole layer comprising said raised solelines and said protuberances; taking said midsole layer out of saidfirst male mould and said first female mould and placing said midsolelayer into a footwear sole-shaped second mould for injection mouldingwith a second formula plastic to form one or more second raised solelines on the upper surface of the midsole layer, the second raised solelines being embedded with the protuberances to thereby anchor the firstraised sole lines with the second raised sole lines.

Advantageously, the provision of bores in the midsole layer allow forbetter anchoring of the first sole lines on one side of the midsolelayer with the second sole lines on the other side of the midsole layerby means of the protruding protuberances being embedded with the secondformula plastic.

Preferably, the sole mould is used to fabricate high-quality soles withgreat efficiency, wherein the sole features good air permeability and issuitable for long-term wear because it can fit snugly with the foot byadapting itself automatically to the shape of the foot.

Preferably, the second mould may further include a second female mouldand a second male mould, both configured in the same shape as a completefoot sole and can fit into each other. Further, the aforementioned firstfemale mould and the first male mould, both resembling the fore part ofthe sole, also match the fore part of the sole-shaped second femalemould and the second male mould. The said second female mould furtherincludes a second downward concave in the same shape as and at thecorresponding position of the first downward concave of the first femalemould. The said second male mould further features a second injectionarea in the same shape as and at the corresponding position of thesecond downward concave. Still further, a second injection hole (whichpasses through the leather layer) is designed on the said secondinjection area. The second male mould further features anupward-concaved third injection area in the rear part of the sole, aswell as a second injection hole (which passes through the leather layer)in the said third injection area. The leather layer, having beenprocessed by the first female mould and the first male mould, is furtherprocessed by the second female mould and the second male mould,generating an injection-moulded shoe sole with an embedded leatherlayer. Meanwhile, a raised injection area is formed on the upper side ofthe said leather layer.

A middle plate may be inserted between the second female mould and thesecond male mould when the two are assembled to process the leatherlayer through injection moulding, so as to produce a cambered or arcuateshoe sole.

Preferably, the first injection hole passes through the first male mouldthrough an injection channel; the second injection hole passes throughthe second male mould through an injection channel.

The soft plastic used may be thermoplastic polyurethane (TPU).Preferably, the first formula plastic is softer than said second formulaplastic.

Preferably, the cylindrical bores and the injection holes have adiameter of about 2 mm to 10 mm.

The sole mould described in this Invention is simple in structure andeasy to operate. It is capable of manufacturing quality foot soles ofgood air permeability with high efficiency. Moreover, these shoe solescan perfectly match the feet by automatically adapting themselves to theshape of the feet, and are therefore suitable for wear for a long time.Moreover, the product yield is relatively high.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side sectional view of a shoe sole formed by the sole mouldand method, according to a preferred embodiment of the presentinvention;

FIG. 2 is a top view of the shoe sole of FIG. 1;

FIG. 3 is a sectional view of a first female mould and a first malemould in an assembled position, according to a preferred embodiment ofthe present invention;

FIG. 4 is a sectional view of a second female mould and a second malemould in an assembled position, according to a preferred embodiment ofthe present invention;

FIG. 5 is a top view of two leather layers used by a sole mould formaking shoe soles, according to a preferred embodiment of the presentinvention;

FIG. 6 is a top view of a left and right first female moulds, accordingto a preferred embodiment of the present invention;

FIG. 7 is a bottom view of a left and right first male moulds, accordingto a preferred embodiment of the present invention;

FIG. 8 is a sectional view of the leather layer of FIG. 5 after beinginjection moulded using a first female mould and a first male mould,according to a preferred embodiment of the present invention;

FIG. 9 is a top view of a left and right second female moulds, accordingto a preferred embodiment of the present invention;

FIG. 10 is a bottom view of a left and right second male moulds,according to a preferred embodiment of the present invention;

FIG. 11 is a flow process of one example of a method for using the solemould, according to a preferred embodiment of the present invention; and

FIG. 12 is a flow process of another example of a method for using thesole mould, according to a preferred embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of this Invention will now be described byreferring to the attached drawings.

Now referring to FIG. 1 and FIG. 2, there illustrated a shoe sole 10fabricated according to a method of the present invention. The shoe solehas good air permeability and is suitable for long-time wear, asmentioned in the Background. This shoe sole 10 fits snugly with the foot(not shown) by automatically adapting itself to the shape of the foot.The main body or midsole layer 12 of the fore sole 14 is illustrativelya leather layer which is primarily made of leather materials. By way ofinjection-moulding soft plastics, one or more first raised sole lines 16and one or more second raised sole lines 18 are formed respectively onan underside 20 of the midsole leather layer 12 to thus form an outersole portion 19 and an upper surface 22 of the midsole leather layer 12to thus form an inner sole portion 17. A rear part 24 of the sole 10 isalso obtained by injection-moulding the same plastics and is integratedwith the leather layer 12 to constitute a complete shoe sole 10. Theraised sole lines 16, 18 are shaped like ribs that define channels inbetween these ribs, which ensure good air circulation.

Now referring to FIG. 3, FIG. 4 and FIG. 5, in addition to FIG. 1, thereis illustrated a sole mould according to an illustrative embodiment ofthe present invention. The sole mould includes two parts: a first mould26 which resembles a fore sole 14 and a second mould 28 which has theshape of a complete foot sole. The first mould 26 and the second mould28 are used successively to produce the shoe sole 10. Firstly, the firstmould 26 is used to treat the leather layer 12, in particular the forepart 14 of the shoe sole 10, by injection moulding, which forms the oneor more first raised sole lines 16 on the underside 20 of the leatherlayer 12. Secondly, the second mould 28 is used to treat the leatherlayer 12 bearing the first raised sole lines 16, resulting in one ormore second raised sole lines 18 on the upper surface 22 of the leatherlayer 12. Meanwhile, the rear part 24 of the shoe sole 10 is obtained byinjection-moulding soft plastics in the second mould 28 such that therear part 24 is integrated with the leather layer 12. A finished sole 10comprising one or more second raised sole lines 18 of the fore sole 14on the upper surface 22 of the midsole 12 to form the inner sole portion17 and the one or more first raised sole lines 16 of the fore sole 14 onthe underside 20 of the shoe sole 10 to form the outer sole portion 19is produced by the moulds, 26 and 28.

Now referring to FIG. 6, in addition to FIG. 1, FIG. 3, FIG. 4 and FIG.5, the first mould 26 further includes a first female mould 32 and afirst male mould 34, both of which are available as a pair to produce apair of shoe soles 10. The first female mould 32 and the first malemould 34 are configured in the same shape as the fore sole 14 of thefoot and fit into each other when assembled as illustrated. The firstfemale mould 32 further contains one or more first downward concavecavities as in 36 and a first raised area 38 which when injectedmoulded, or infused with plastic, form the raised sole lines 16 on theunderside 20 of the leather layer 12.

Now referring to FIG. 7 and FIG. 8, in addition to FIG. 3, the firstmale mould 34 includes one or more cylindrical bores 40 and one or morefirst injection holes 42 in a first injection area 44 each one of whichare in fluid communication with one of the one ore more first downwardconcave cavities 36 via each of one or more second injection hole 45 andeach of one or more second cylindrical bore 47 respectively provided forin the layer 12. The one or more second cylindrical bores 47 and the oneor more second injection hole 45 provide fluid communication for theplastic between the one or more first downward concave cavities 36 andthe one or more first cylindrical bores 40 and the one or more firstinjection holes 42 through the layer 12 when respectively alignedtherewith. Illustratively, through the one or more first injection hole42, each of which are in fluid communication with an injection channel46, soft plastic is supplied from the injection channels 46 to beinfused into the one ore more first downward concave cavities 36 via theone or more second injection holes 45. Once plastic is infused into theone or more first downward concave cavities as in 36, plastic is allowedto pass through the layer 12 via the one or more second cylindricalbores as in 47 and into the one or more of first cylindrical bore 40provided for in the first male mould 34 such that one or more plasticprotuberances as in 49 are embedded within the midsole layer 12 andextend from the upper surface. The first female mould 32 and the firstmale mould 34 are then assembled to mould the plastic, leaving the oneor more first raised sole lines 16 on the under side 20 of the leatherlayer 12.

Now referring to FIG. 9 and FIG. 10, the second mould 28 furtherincludes a second female mould 48 and a second male mould 50, both ofwhich are available in pair to produce a pair of shoe soles 10. The saidsecond female mould 48 and second male mould 50 are configured in thesame shape as a complete foot sole 10 and can fit into each other.Furthermore, the aforementioned first female mould 32 and the first malemould 34 also match the fore part 14 of the sole-shaped second femalemould 48 and the second male mould 50. The second female mould 48further includes one or more second downward concave cavities as in 52in the same shape as and at the corresponding position of the one ormore first downward concave cavities as in 36. The second male mould 50further features a second injection area 54 comprising one or moresecond upward concave cavities as in 55 in the same shape as and at thecorresponding position of the one or more second downward concavecavities as in 52. Still further, one or more second injection holes 56are provided in the second injection area 54 for each of the one or moresecond upward concave cavities as in 55.

Still referring to FIG. 10, the second male mould 50 further features anupward-concaved third injection area 58 to form the rear part 24 of thesole 10 when it is injected moulded, as well as a second injection hole56 for injecting plastic into the third injection area 58. The leatherlayer 12, having been processed using the first female mould 32 and thefirst male mould 34, is further processed using the second female mould48 and the second male mould 50, generating an injection-moulded shoesole 10 with an embedded leather layer 12 by infusing soft plastic intothe second injection area 54 and the third injection area 58 through thesecond injection hole 56 and the injection channels 46. As a result, theone or more second raised sole lines 18 are formed on the upper surface22 of the leather layer 12.

It should be noted that the soft plastic being used for injectionpurposes for the sole mould described herein is illustrativelythermoplastic polyurethane (TPU). Illustratively, the plastic used toform the one ore more first raised sole lines 16 may be harder than theplastic used to form the one or more second raised sole lines 18.

Now referring back to FIG. 1 and FIG. 4, the sole mould provided in thepresent Invention further includes a middle plate 60, which is insertedbetween the second female mould 48 and the second male mould 50 when thetwo are assembled for injection moulding the leather layer 12. Theultimate purpose is to produce a curved shoe sole, for instance thecurved rear part of high-heeled leather shoes for women.

The sole mould described in this Invention is simple in structure andeasy to operate. It is capable of manufacturing quality foot soles ofgood air permeability with high efficiency. Moreover, these shoe soles10 can perfectly match the feet by automatically adapting themselves tothe shape of the feet, and are therefore suitable for wear over a longperiod of time. Moreover, the product yield is relatively high.

Now referring to FIG. 12, there is provided an illustrative example ofthe method of using the sole mould which comprises the following steps.

Step S102: Assemble the fore sole-shaped first mould 26 onto aninjection machine (not shown). After that, place the leather layer 12into the first mould 26 for injection moulding to form the first raisedarea 38 on the underside 20 of the leather layer 12 comprising one ormore first raised sole lines 16.

Step S104: Take the leather layer 12 out of the first mould 26 and putit into the foot sole-shaped second mould 28 for injection moulding toproduce a shoe sole 10 with an embedded leather layer 12 comprising thesecond raised injection area 54 on the upper surface 22 of the leatherlayer 12 comprising the one or more second raised sole lines 18.

Now referring to FIG. 12, there is provided another illustrative exampleof the method of using the sole mould is composed of the followingsteps:

Step S202: Assemble the fore sole-shaped first female mould 32 of thefirst mould 26 onto the injection machine. Place the leather layer 12 ontop of the first female mould 32 with the underside 20 facing downwardsand align the each pre-designed one or more second cylindrical bores 47and one or more second injection holes 45 on the leather layer 12 withthe each of the one or more first downward concave cavities 36 of thefirst female mould 32.

Step S204: Assemble and fix the fore sole-shaped first male mould 34 andthe first female mould 32, making sure that each of the firstcylindrical bores 40 and each of the first injection holes 42 located onthe first male mould 34 are aligned with each of second cylindricalbores 47 and each of the second injection holes 45 on the leather layer12 respectively. Then, place a puller plate 64 on top of the first malemould 34.

Step S206: By way of the one or more first injection hole 42 and the oneor more injection channels 46, infuse the soft plastic into the firstmale mould 34 by using an injection machine (not shown). The softplastic, after going through the one or more first injection holes 42 onthe first male mould 34 is channelled into the one or more firstdownward concave cavities 36 of the first female mould 32 and shaped up,resulting in the first raised area 38 on the underside 20 of the leatherlayer 12 to form the first one or more first raised sole lines 16.Further, the soft plastic inside the one or more first downward concavecavities 36 moves through the one or more second cylindrical bores 47 ofthe leather layer 12 and into the one or more first cylindrical bores 40to form one or more pyramidal protuberances 49, which are integratedwith the leather layer 12. After that, the first male mould 34 and thefirst female mould 32 are split to remove the leather layer 12 bearing afirst injection area 44 on the underside 20.

Referring back to FIG. 5, it is preferable to pre-punch the midsolelayer 12 to form holes matching with the cylindrical bores 47 and theinjection holes 45 prior to placing the midsole 12 on top of the firstfemale mould 32. Alternatively, the cylindrical bores 47 and theinjection holes 45 may be punched in the midsole 12 once the midsole isin the first female mould 32.

Step S208: Assemble the foot sole-shaped second female mould 48 of thesecond mould 28 onto the injection machine and place the middle plate 60on the said second female mould 48. Lay up the leather layer 12 onto themiddle plate 60, making sure that the underside 20 of the leather layer10 faces downward and that the first injection area 44 on the underside20 of the leather layer 10 shall match with the second downward concavecavities 52 of the second female mould 48. The final purpose is toproduce arcuation on the leather layer 12;

Step S210: Assemble and fix the foot sole-shaped second male mould 50and the second female mould 48 of the second mould 28, making sure thatthe second injection area 54 of the second mould is aligned with the oneor more second downward concave cavities 52. When aligned, the one ormore pyramidal protuberances 49 on the leather layer 12 are suspended,or project, inside the second injection area 54. Then, place the pullerplate 64 on top of the second male mould 50.

Step S212: By way of the one or more second injection holes 56 on thesecond male mould 50 and the one or more injection channels 46, infusethe soft plastic into the second male mould 50 by using an injectionmachine. The soft plastic is moulded into a shoe sole 10 to combine withembedded leather layer 12 and the one or more pyramidal protuberances 49inside the second injection area 54 and the third injection area 58.During this process, the one or more pyramidal protuberances 49 asmentioned in Steps S206 and S210 are embedded into the plastic injectedinto the one or more second upward concave cavities 52, thereforeleaving a second raised injection area 54 of second raised sole lines 18on the upper surface 22 of the leather layer 12.

Easy to operate, the sole mould described in this Invention is capableof manufacturing quality shoe soles of good air permeability with highefficiency. These shoe soles can perfectly match the feet byautomatically adapting themselves to the shape of the feet, and aretherefore suitable for wear over a long time. Moreover, the productyield is relatively high.

The shoe sole is particularly comfortable to wear when using a leathermidsole. Indeed, because of the relatively high elasticity of leather,the shoe sole may wrap up feet of different shapes. Because parts of theleather midsole are not covered with plastic, it provides with good airpermeability and ventilation. The shoe sole is comfortable, cooler anddrier compared to other existing shoe soles and solves problems oflong-time wearing, poor air permeability, dampness and heating.

1. A method for forming a footwear sole comprising a fore sole and arear sole, the method comprising: providing a midsole layer having oneor more midsole injection holes and one or more midsole boresdistributed thereon, the midsole injection holes and the midsole boresextending between an underside of the midsole layer and an upper surfaceof the midsole layer; providing a first female mould comprising one ormore first downward concave cavities and first raised areas; placingsaid midsole layer onto said first female mould, and aligning saidmidsole injection holes and said midsole bores with said first downwardconcave cavities provided in said first female mould; providing a firstmale mould comprising a first injection area comprising one or more offirst bores and one or more first injection holes; assembling and fixingsaid first male mould and said first female mould so that each of saidmidsole bores and said midsole injection holes are respectively alignedwith each of said first bores and each of said first injection holes;and a step A3 comprising infusing a first formula plastic into saidfirst male mould by way of said first injection holes and said midsoleinjection holes into said first downward concave cavities, wherein saidfirst formula plastic is channeled through each of said first injectionholes and each of said midsole injection holes into each of saiddownward concave cavities and shaped up resulting in raised soles lineson said fore sole, and further wherein said first formula plastic insideeach of said first downward concaves passes through each of said midsolebores and into each of said first bores to form one or moreprotuberances which are embedded with said midsole layer; and splittingsaid first male mould and said first female mould to remove said midsolelayer comprising said raised sole lines and said protuberances; and astep B comprising taking said midsole layer out of said first male mouldand said first female mould and placing said midsole layer into a shoesole-shaped second mould for injection moulding with a second formulaplastic to form one or more second raised sole lines on the uppersurface of the midsole layer, the second raised sole lines beingembedded with the protuberances to thereby anchor the first raised solelines with the second raised sole lines.
 2. The method of claim 1,wherein said step B comprises: a step B1 comprising providing a secondfemale mould and placing said midsole onto said second female mould sothat said first raised lines match with said one more second downwardconcaves of said second female mould; a step B2 comprising providing asecond male mould comprising a second injection area comprising one ormore second upward concave cavities and one or more second injectionholes and assembling and fixing said second male mould and said secondfemale mould, such that each of said one or more protuberances protrudesinside each of said one or more second upward concave cavities; and astep B3 comprising infusing said second formula plastic into each ofsaid one or more second upward concave cavities through said one or moresecond injection holes such that said second formula plastic is mouldedwith said midsole layer and with each of said one or more protuberancesto form said one or more second raised sole lines on the upper surfaceof the midsole layer.
 3. The method of claim 2, wherein said step B1further comprises: positioning a middle plate on top of the said secondfemale mould; placing said midsole layer on said middle plate; matchingsaid first raised injection area on said underside with said one or moresecond downward concave cavities of said second female mould; andinfusing said second formula plastic into an upwardly-concaved thirdinjection area for forming said rear sole.
 4. The method according toclaim 1, wherein said first formula plastic is softer than said secondformula plastic.
 5. The method according to claim 1, wherein said boresand said injection holes have a diameter of 2 mm to 10 mm.
 6. The methodaccording to claims 1, wherein said midsole layer comprises leather. 7.A footwear sole fabricated according to the method of claim 1.